axios.post('/api/insertStudent', {
  sunNum: 66,
  stuName: '牛逼',
  stuClass: '卓识班',
  age: 38
  
})
  .then(function (response) {
    console.log(response);
  })
  .catch(function (error) {
    console.log(error);
  });

const upload = document.querySelector('.upload');
upload.addEventListener('click', function () {
  const file = document.getElementsByClassName('file')[0].files[0];
  const form = new FormData();
  form.append('file', file);
  axios.post('/upload', form)
    .then(res => {
      console.log(res);
    })
    .catch(err => {
      console.log(err);
    });
});